This invention concerns grommets installed in panel holes to seal to elongated elements such as electrical or control cables passed through the panel holes and also are used to seal panel access holes. Grommets are pushed into the panel hole until a capturing feature passes through the hole and then springs out to capture the grommet against a sealing flange pressed against the opposite entry side of the panel. Grommets have in the past been constructed of soft rubber or other elastomers to insure an effective sealing pressure on the cable and panel surfaces.
However, the lack of stiffness has allowed the grommet to be dislodged from the panel by pressure exerted by the cable, particularly when the cable extends at a severe angle to grommet. There have heretofore been developed “dual durometer” grommets which have hard plastic portions embedded in a softer sealing elastomer. The panel mating portions have still been constructed of soft material such that dislodgement resistance is still not satisfactory in all applications.
Other problems include the necessity of exerting a high force on the grommet to install the grommet, and the difficulty assemblers have in determining when a grommet is fully seated.
It is an object of the present invention to provide a grommet which has a high resistance to dislodgment from the panel hole in which it is installed while still effectively sealing to a cable passed through the grommet and the panel hole.
It is another object of the invention to provide a grommet which is easily installed and provides an indication to the assembler when proper seating of the grommet has been achieved.